U.S. Pat. No. 3,966,190 to Grant discloses top feeding from an upwardly biased stack of documents through a throat structured to accommodate a single document's passage therethrough. A composite D roller is used to separate the topmost sheet and urge it through the throat opening. The structural members forming the throat, however, are in fixed position for a document feeding sequence.
Commonly assigned U.S. patent application Ser. No. 617,763 to Parks et al filed June 6, 1984, discloses a dual compartment cut sheet hopper for attachment to a printer or the like and includes movable corner buckler edge restraints adapted to maintain contact with the uppermost sheet in the hopper during a feed cycle.